The FileHelpers are an easy to use .NET library written in C#. Is designed to read/write data from flat files with fixed length or delimited records (CSV). Also has support to import/export data from different data storages (Excel, Access, SqlServer)
Code on GitHub: https://github.com/MarcosMeli/FileHelpers
Bugs/Ideas: http://filehelpers.myjetbrains.com/youtrack/rest/agile/FH/sprint

OpenQuickBooks is an open source accounting software.It is an accounting software similar to QuickBooks.It`s main tasks:Track sales and expenses,Easily create and manage invoices,Create and send purchase orders.C# developers are welcome.Talley